Safety device in the sheet feeder

Abstract

A safety device with two conveying systems in the sheet feeder of a machine, capable of processing a sheet-shaped material. An objective of the invention is to construct a generic sheet feeder for large-format machines so that only stacks with a specified maximum weight can reach the processing stage. The present invention encompasses a weighing device ( 22, 28 ) located in the sheet feeder ( 1 ), which determines the weight of the stack ( 4 ), is positioned on the stack carrier ( 3 ) and is connected with a regulating and controlling device ( 19 ) controlling the driving mechanism ( 8 ). At least one permissible total weight is stored in the regulating and controlling device ( 19 ). The regulating and controlling device ( 19 ) compares the weight of the stack with said stored permissible total weight and the driving mechanism ( 8 ) is activated only if the weight of the stack does not exceed the permissible total weight.

1. A machine which processes sheet-shaped material, having an apparatus comprised of a weighing device, a regulating and controlling device, a driving mechanism, a conveying system, a stack carrier, and a separating and conveying device;
 wherein said regulating and controlling device is connected to both said weighing device and said driving mechanism, with said driving mechanism further connected to said conveying system, and said conveying system operationally connected to said stack carrier; and 
 wherein at least one permissible weight is stored in said regulating and controlling device and said regulating and controlling device compares said stored permissible weight to the weight of the stack determined by said weighing device and activates said driving mechanism only if said weight of the stack does not exceed said stored permissible weight, and can either lift said stack carrier from a stack-taking position after said stack carrier has taken a stack of sheet-shaped material or can lower said stack carrier after the singulating and discharging of the sheet-shaped material by said separating and conveying device; and 
 wherein said apparatus further comprises an auxiliary stack carrier, wherein if said weight of the stack does not exceed said stored permissible weight, said driving mechanism can lower said stack carrier after the transfer of said stack to said auxiliary stack carrier. 
 
   
   
     2. The machine of  claim 1 , wherein a permissible auxiliary total weight, a permissible total weight less an auxiliary stack weight carried by said auxiliary stack carrier, is stored in said regulating and controlling device. 
   
   
     3. The machine of  claim 1 , wherein a permissible auxiliary total weight, stored as a nominal weight, will cause said regulating and controlling device to activate said driving mechanism, which will in turn operate said auxiliary stack carrier. 
   
   
     4. The machine of  claim 3 , wherein said permissible auxiliary total weight can compulsorily be realized as a nominal value responsible for the operation of said apparatus with said auxiliary stack carrier. 
   
   
     5. The machine of  claim 1 , wherein said auxiliary stack carrier contains a device which detects the weight of the auxiliary stack. 
   
   
     6. The machine of  claim 1 , wherein an auxiliary conveying system associated with said auxiliary stack carrier contains a device which detects the weight of an auxiliary stack. 
   
   
     7. A machine which processes sheet-shaped material, having an apparatus comprised of a weighing device, a regulating and controlling device, a driving mechanism, a conveying system, a stack carrier, and a separating and conveying device;
 wherein said regulating and controlling device is connected to both said weighing device and said driving mechanism, with said driving mechanism further connected to said conveying system, and said conveying system operationally connected to said stack carrier; and 
 wherein at least one permissible weight is stored in said regulating and controlling device and said regulating and controlling device compares said stored permissible weight to the weight of the stack determined by said weighing device and activates said driving mechanism only if said weight of the stack does not exceed said stored permissible weight, and can either lift said stack carrier from a stack-taking position after said stack carrier has taken a stack of sheet-shaped material or can lower said stack carrier after the singulating and discharging of the sheet-shaped material by said separating and conveying device; and 
 wherein a second weighing device is associated with said conveying system. 
 
   
   
     8. The machine of  claim 7 , wherein said conveying system comprises tension elements and said second weighing device is associated with at least one of said tension elements. 
   
   
     9. The machine of  claim 8 , wherein said conveying system comprises four tension elements and said second weighing device is associated with at least one of the four tension elements. 
   
   
     10. The machine of  claim 8 , wherein said conveying system comprises at least two tension elements, which are guided over deflector rolls positioned in a frame of said sheet feeder, and said second weighing device is associated with at least one deflector roll. 
   
   
     11. The machine of  claim 8 , wherein said second weighing device comprises at least one measuring device. 
   
   
     12. A machine which processes sheet-shaped material, having an apparatus comprised of a weighing device, a regulating and controlling device, a driving mechanism, a conveying system, a stack carrier, and a separating and conveying device;
 wherein said regulating and controlling device is connected to both said weighing device and said driving mechanism, with said driving mechanism further connected to said conveying system, and said conveying system operationally connected to said stack carrier; and 
 wherein at least one permissible weight is stored in said regulating and controlling device and said regulating and controlling device compares said stored permissible weight to the weight of the stack determined by said weighing device and activates said driving mechanism only if said weight of the stack does not exceed said stored permissible weight, and can either lift said stack carrier from a stack-taking position after said stack carrier has taken a stack of sheet-shaped material or can lower said stack carrier after the singulating and discharging of the sheet-shaped material by said separating and conveying device; and 
 wherein the top side of said stack carrier is at floor level when said stack carrier is in the position to take another stack. 
 
   
   
     13. The machine of  claim 12 , wherein said stack carrier rests with its underside on said first weighing device when said stack carrier is in the position to take another stack. 
   
   
     14. A machine which processes sheet-shaped material, having an apparatus comprised of a weighing device, a regulating and controlling device, a driving mechanism, a conveying system, a stack carrier adapted to receive a preassembled stack from a stack-taking position, and a separating and conveying device;
 wherein said regulating and controlling device is connected to both said weighing device and said driving mechanism, with said driving mechanism further connected to said conveying system, and said conveying system operationally connected to said stack carrier; and 
 wherein at least one permissible weight is stored said regulating and controlling device and said regulating and controlling device compares said stored permissible weight to the weight of the stack determined by said weighing device and activates said driving mechanism only if said weight of the stack does not exceed said stored permissible weight, and can either lift said stack carrier from a stack-taking position after said stack carrier has taken a stack of sheet-shaped material or can lower said stack carrier after the singulating and discharging of the sheet-shaped material by said separating and conveying device; 
 wherein a first weighing device is associated with said stack carrier; and 
 wherein two measured value transducers for detecting the weight of said stack are positioned diagonally opposite to one another in said first weighing device. 
 
   
   
     15. A machine which processes sheet-shaped material, having an apparatus comprised of a weighing device, a regulating and controlling device, a driving mechanism, a conveying system, a stack carrier adapted to receive a preassembled stack from a stack-taking position, and a separating and conveying device;
 wherein said regulating and controlling device is connected to both said weighing device and said driving mechanism, with said driving mechanism further connected to said conveying system, and said conveying system operationally connected to said stack carrier; and 
 wherein at least one permissible weight is stored in said regulating and controlling device and said regulating and controlling device compares said stored permissible weight to the weight of the stack determined by said weighing device and activates said driving mechanism only if said weight of the stack does not exceed said stored permissible weight, and can either lift said stack carrier from a stack-taking position after said stack carrier has taken a stack of sheet-shaped material or can lower said stack carrier after the singulating and discharging of the sheet-shaped material by said separating and conveying device; 
 wherein a first weighing device is associated with said stack carrier; and 
 wherein said first weighing device is formed from a stationary lower frame and an upper frame, wherein said upper frame can be shifted in a vertical direction, is associated with the lower frame and is supported at four stops, two of which are constructed as measured value transducers.